1. Field
An embodiment of the present invention relates to an optical imaging device, and more particularly, to an optical imaging device including a flexible image sensor.
2. Description of the Related Art
A camera capable of storing an image as digital information is being continuously developed. A photographing system of the camera includes an image sensor capable of storing optical intensity information. The image sensor may be, for example, a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device. On the other hand, the image sensor may be formed of a plurality of optical sensor arrays. Studies on the camera including the image sensor capable of having a larger view angle, a higher magnification zoom function, and an image with higher magnification, are being performed. For this purpose, a technology of precisely removing aberration is required.
The aberration mostly increases more at an edge of the image sensor than in a center of the image sensor, which distorts an image. An image of an object is focused on the image sensor through a lens. At this time, light incident on an optical axis of the lens in parallel is correctly focused on an image sensor surface. However, light that forms an angle with the optical axis of the lens, that is, that is incident in an off-axis manner is focused in front of or behind the image sensor without being correctly focused on the image sensor due to the aberration. Therefore, a clear image may be obtained in the center of the image sensor, but a blurred and distorted image is obtained at the edge of the image sensor due to the aberration.
On the other hand, a phenomenon in which the magnification of the image varies with a magnitude of an angle of light incident on the lens so that lateral magnification of the image changes in accordance with a distance from the optical axis is referred to as distortion aberration. When an object such as wire mesh is photographed in parallel with the image sensor surface, the distortion aberration remarkably occurs. Distortion becomes severer toward the edge of the image so that the image is distorted. The distortion aberration has nothing to do with clearness of the image. However, since the distortion aberration matters in measurement or an astronomical observation, the distortion aberration needs to be corrected.